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Entries in material world (10)

Monday
Sep192011

material world: hemp

preparing hemp yarns for weavingphoto by: dunks-a-lot Hemp is—again—gaining popularity for its inherent characteristics: strength, durability, fast growth, and its friendliness to the environment since it needs fewer substances to control pests and/or weeds. A bonus is that its fibers are stronger when the plant is younger—which means it spends less time in farm fields taking up valuable real estate.

photo by: SweetOnVeg Hemp has been used for thousands of years in the making of household goods—it’s one of the earliest domesticated plants—but unfortunately it fell out of favor in the US after the Marihuana Tax Act of 1937 was passed.

The soft, brawny fibers of hemp for industrial production come from the Cannabis plant—its genus significantly lower in THC (tetrahydro-cannabinol) than narcotic strains and it grows quite differently as well, especially in height.

Its versatility and benefits, specifically as a fiber used in paper and cloth production, are ironically what may have caused its growth to be restricted to this day. It’s suspected that some paper and cotton industrialists lobbied in favor of the Act—seemingly by blurring the difference between it and its narcotic cousin—thereby protecting their own interests.

Compared to cotton, hemp cloth can be stronger and last longer—durable rugs, ropes and cording can be made from these fibers as well. Due to its fiber structure, colorfastness can be an issue if dyed—especially for darker tones—and some shedding should be expected, similar to jute and wool.

Beyond paper and textiles, today hemp is being used in biodegradable plastics, home insulation, fuel and health foods.

Its seeds are rich in heart-healthy, essential fatty acids, amino acids, vitamins and minerals. They’re also pressed to make ‘milk’ which is both dairy and gluten-free.

As a crop, hemp seems to have tremendous untapped potential since it can be grown for food, fuel, daily necessities, tools and building materials. But also as animal bedding, horticultural mulch, and to clear impurities out of wastewater, sewage—even contaminants at the Chernobyl nuclear reactors.

photo by: Jordanhill School D&T Dept

Friday
May062011

material world: eucalyptus

Eucalyptus is a diverse type of flowering tree within the myrtle family. There are over 700 species, most of which are native to Australia, and only about 9 can’t be found there.

Eucalyptus are favored as a fast-growing sustainable resource, similar to bamboo, and all of the tree—it’s wood, leaves, flowers—are broadly used.photo by: Umesh Behari Mathur

First, the flower blossoms provide nectar for insects, birds, bats, etc. and essential oils from its leaves contain natural disinfectants so it’s used in cleaning products, deodorants, toothpaste, decongestants and cough/cold medicines.

Its also a key food source for some koala and possum who are tolerant of those chemicals which can be toxic in large doses.photo by: puuikibeach

On both a positive and negative note, eucalyptus trees require lots of water.

In swamp-like areas, planting them can reduce soil erosion and malaria bearing mosquitoes—ironic considering its inherent insect repellent properties—but in normal to dry or non-indigenous areas, they can prohibit other plants and native plants from thriving.

Such is the case in California where eucalyptus trees were introduced in the mid 1800s with the hopes that their fast growth would offer a vast supply of railroad ties as miles of new tracks were laid during the Gold Rush.

Unfortunately, wood from younger trees warped dramatically and wood from older trees was so dense that nails couldn’t easily secure them in place—both characteristics sealed its fate.

Although its favored as a windbreak and for curbing erosion, it’s disliked for its role in feeding forest fires (read on) and regenerating from mere trunks, so currently measures are being taken to reduce its population there.

Types of eucalyptus plants and trees have been carbon dated to tens of millions of years ago—around the time charcoal deposits have been dated as well—which is interesting since they share a common trait.

As a living plant, and at high temperatures, eucalyptus oil can be emitted as a vapor—which creates the characteristic blue haze of Australia’s landscape, shown above—but it can also be highly flammable, like charcoal.

But the wood becomes more dense—and therefore stronger, much like teak—so it’s also prized for its durability outdoors while those same natural oils help protect it from the elements.

Like most woods, eucalyptus weathers to a soft silvery grey but tung oil can be applied periodically to help preserve its original patina.

Wednesday
Apr202011

sunlight = vitamin D

Did you know that vitamin D is produced naturally in the skin when exposed to the sun’s ultraviolet rays? Similar to a steroid in molecular composition, vitamin D circulates as a hormone and promotes healthy bones and muscles while boosting the immune system.

According to research by the Mayo Clinic, it’s believed that “vitamin D may offer protection from type 1 diabetes, multiple sclerosis and rheumatoid arthritis by reducing inflammation and strengthening the immune system.”

The trick is getting enough rays for a good supply of vitamin D, but using sunblock as protection against too much sun—if you’ll be in direct sunlight for an extended period of time. It’s all about balance—and getting outdoors.

Tuesday
Apr052011

material world: aluminum

Aluminium, or aluminum, is a silvery white chemical element that happens to be the third most abundant element after oxygen and silicon. It is however the most abundant metal since it accounts for about 8% of Earth’s solid surface weight.

Similar to iron, aluminum is extracted from other elements—mostly bauxite ore via electrolysis—and can be found combined in almost 300 different types of minerals.

photo by: libbyrosot

It’s one of the most versatile materials—lightweight and pliable as a thin sheet of foil, or dense, sturdy and heavy when cast.

Cast aluminum, left and below, is a fairly Medievil process where aluminum is heated to a liquid form, then carefully poured into a mold—or packed sand which has been shaped by a mold pressing.

It does however take time and talent to create the molds, to shave or sand off excess aluminum, to solder pieces together, then to polish the rough casting to a mirror-like finish.

photo by: außerirdische sind gesund

As an extruded aluminum tube, shown right, it falls in the middle since it’s lightweight and incredibly sturdy—making it an ideal material to use for furniture and bicycle frames.

With a melting point of 1220°F, aluminum is perfect for cookware and bakeware. Whether as a muffin cup, anodized aluminum pots or foil baking pans, they all conduct heat well but remain fairly cool.

Salts can oxidize the finish—actually creates a protective surface, passivation, which acts as a barrier and protects the aluminum underneath; and aluminum doesn’t rust so it’s particularly favored by the aerospace industry, for many types of outdoor furniture, and as aluminum siding and trim for buildings and homes.

photo by: blondewarningAluminum has been produced for commercial use for just over 100 years but during Napoleon III’s time—1848-1852—it was considered a precious metal even more valuable than gold.

During Jimmy Carter’s Presidency, beer can collections gained popularity and value when his brother Billy Carter introduced Billy Beer.

It was around that time that fully detachable tabbed openers gave way to the current attached version since many had been ‘stored’ in the can, then swallowed accidentally.

Since the late 1960s, when beverages switched from tin cans, aluminum has again achieved superior status since transportation costs are less due to the lighter weight and more recycling can be done instead of mining virgin aluminum.

100% recyclable with very little prep or stripping to be done, aluminum is one of the most recycled materials since it’s easy to gather, cost-effective to recycle—it takes about 5% of the energy to process vs producing virgin material—and when recycled, aluminum maintains most if not all of its natural properties.

Because of these inherent characteristics, a high percentage of cans, vehicles and construction materials, like siding, are consistently recycled throughout the world.

Friday
Sep172010

material world: clear glass

Transparent or sandblasted, mouth-blown or machine-made, borisilicate or soda…glass. It can take on almost any form imaginable—from purely functional window panes and high performance lab glass to art glass and brilliant crystal chandeliers—the basics don’t do justice to this most versatile material.

Most likely an accidental creation of residue chemicals in an oven, pieces have been discovered in Mesopotamia from 3000BC and Egypt from the late Bronze Age…so much for its delicate nature.

While most transparent glass has a slight green or blue tint—which is caused by iron that acts as a lubricant in the manufacturing process—‘crystal clear’ lead glass is made with lead oxides, instead of calcium, and is usually used for cut stemware or sparkling crystal jewelry. And even though glass has no crystalline structure chemically, the term stuck like qwerty keyboards. Early window panes, photo courtesy of: lady_lbrty

Generally speaking, most commercial glass made today is soda glass—a mix of sodium carbonate from soda ash, calcium oxides from limestone, magnesium and aluminum oxides. Heated to temperatures over 2000°F, glass begins as a thick liquid—with a high viscosity—and takes shape as it cools. Shapes can be made by literally mouth-blowing the glass through a long pipe or by machines and molds. Blown glass can be thick or thin and fine, like lumi candleholders, while machine made glass is usually thicker like bari bowls.

As further testament to its durability, glass has been battling the elements of nature as an architectural material for hundreds of years. Stained glass windows brought drama to Medieval stone cathedrals, and early window panes were actually mouth-blown into a flat shape which can be easily identified by their wavy surface and circular centers. In more recent centuries, and in its simplest ‘float glass’ form, they’re the key element of modern structures—from high-rise skyscrapers to International Style homes.

Farnsworth House, photo courtesy of: tinyfroglet